Automatic circuit breaker



Oct. 5, 1937. J. sAcHs AUTOMATIC CIRCUIT BREAKER Original Filed Nov. 8, 1934 2 Sheets-Sheet 1 Oct. 5, 1937. J. sAcHs Y AUTQMATIC CIRCUIT BREAKER Original Filed Nov.. 8,' 1934l 2 Sheets-Sheet 2 fr/.ent Uf' JUS 51p@ -Ll/ Patented Oct. 5, 1937 UNITED STATES PATENT OFFICEl Application November 8, 1934, Serial No. 752,154 Renewed September 24, 1936 30 Claims. (Cl. 200-116) vThis invention relates particularly to an automatic circuit breaker of the type set forth in my l directly upon the contact carrying member so as to be bodily movable therewith; van electroresponsive means such as a vbi-metallic thermostatic stripis secured to the contact carrying memberand engages directly with the actuator to prevent movement thereof relatively to the contact member; and an operating means is con.

nected with the actuator and serves to move it and to thus move the .contact member to open and close the circuit. Upon the attainment of abnormal current conditions in the circuit the electro-responsive means releases the actuator, thus permitting it to move relatively to the contact member and thus permitting the contact member to automatically moveto open-circuit position.

v For some purposes it is preferable to make use of a rectilinearly movable contact carrying member instead of a pivotally movable member. The rectilinearly movable member ordinarily requires less space, can be more readily assembled with or disassembled from thev other circuit breaker parts, and provides. a better toggling action for locking in closed-circuit position. The principal object of the present invention is to provide a. circuit breaker of the type set forth having a rectilinearly movable contact carrying member and at the same time vhaving many o i the advantages incident to the circuit breaker set forth in-my last said patent. In the accompanying drawings I have shown 4o the embodiment of the invention which I'now deempreferable, but it will be understood that the drawings are intended for illustrative purposes only and are not to be construed as denning or limiting the scope of the invention, the

.45 claims forming a part of this specication being relied upon for that purpose.

Of the drawings: v Fig. 1 is a front View of a circuit breaker embodying the invention, the said circuit breaker being enclosed in a metallic box .the front cover of which is partly broken away.

Fig. 2 is a side View of the circuit breaker, the lenclosing boxvbeing shown in vertical section.

Fig. 3 is a front view of the circuit breaker with '.55 the front cover thereof removed.

`predetermined position.

Fig. 4 is a vertical sectional view taken along the line 4&4 of Fig.3.

Fig. 5 is a horizontal sectional view taken along the line 5 5 of Fig. 4.

Fig. 6 is a detail view showing separately the 5 frontl guide plate of the circuit breaker and various other parts directly associated therewith.

Fig. 7 is a detail view showing Separately the several parts of the contact carrying member.

Fig. 8 is a vertical sectional viewvtaken along 10 the lines 8-'8 of Fig. 3, but showing the parts in open-circuit position.

Fig. 9 is a view similar to Fig. 8 but showing the parts in closed-circuit positions.

Fig. 1D is a View similar to Fig. 9 showing the 15 handle` held in closed-circuit position and showing the Contact member in open-circuit position.

Fig. l1 is a fragmentary sectional view similar to Fig. 4 and showing an alternative embodiment of the invention, this view being taken along the -20 line II-Il of Fig.' 12.

Fig. 12 is a fragmentary rear View of the construction shown in Fig. 11.

.Referring to the drawings, l represents as an entirety the main insulating base or casing for 25 the circuit breaker and 2 represents the front .insulating cover. 'I'hese parts are connected by suitable means, such as screws 3, 3, and together` they constitute an enclosure. As shown, the front ends of the screws 3, 3 are engaged with 30 brackets 4, 4 which may serve as a means for supporting the circuit breaker. The circuit breaker is shown mounted i'n a box 5 having supporting ears 6, 6 therein. The brackets 4, 4' engage the ears 6, 6 and are connected thereto by 35 means of screws 1, 1. The front cover 8 of the box may be held in place by means of screws 9, 9 entering threaded holes in the brackets 4, 4.- It wifl be understood that the box 5 is provided with the usual openings or knockouts, such as 5a, 5, 40 permitting circuit wires to extend -into the box for connecting the circuit breaker.

The circuit breaker is provided with a horizontally pivoted handle or operating member I0 which projects through a suitable slot in the 45 front cover 8. As shown, the cover is provided with metallic guards-'II placed at oppOsite sides of the handle. The guards have holes Ila fory receiving a sealor lock to hold the handle in'a 50 Fig. 3 shows the'circuit breaker with the front insulating cover 2 thereof removed. The main casing I has an opening or recess at the front and is closed or substantially closed at the rear. A

1 tially closes the front of the recess in the casing I. Resting upon the guide plate I2 are two conducting membeis I3 and I4 which are identical construction except that they are right andle Each of the members I3 and I4 is held in place y means of screws I5, I5 which extend forw d through the casing I and through holes in the plate I2. The screws I5, I5 thus serve not only to hold the members I3 and I4 but also to hold the plate I2.

The members I3 and I4 are provided with wire terminals I6 and I1 which are shown as being at v the lower ends thereof. 'The members I3 and I4 are provided with rearward extending portions I3* and I4 which are positioned. in suitably formed notches in the sides of the plate I2. Carried by and electrically connected with the said portions I3a and I4 are resilient conducting elements I3 and I9 which carry contacts 20 and 2|. The said contacts 20 and 2I are stationary except for such movement as is provided by theresiliency of their supports I8 and I9 and they vwill be hereinafter referred to as stationary contacts.

The members I3 and I4 are provided with forward projecting earsv I3b and I4b whichserve to support the before mentioned pivotally mounted handle III. The handle is provided with hubs 22 having axially positioned pintles 23 seated in bearing apertures in the said ears I3b and I4b. A coil spring 24 surrounds on of the handle hubs and serves to bias the handle in the clockwise direction. A portionof the handle II) projects rearward through .a slot I2l in the plate I2. The handle is preferably formed of insulating material and itcarries a metallic piece 25 adapted to be connected with operating links to be hereinafter described.

The contact carrying member of the circuit breaker is rectilinearly movable within the recess in the casing I, the said member being guided at the front and held in place by means of the before mentioned guide plate I2. The said contact carrying. member preferably comprises two insulating plates 26 and 21 which are spaced apart transversely. The two plates 26 and 21 are adapted to engage at the front directly with the guide plate I2. At the rear there is preferably provided an auxiliary guide plate 23 seated in the bottom of the main recess in the casing I.

Two laterally projecting movable contacts 29 and 30 are carried by the contact member lat the sides thereof, these contacts projecting laterally from the respective side plates 26 and 21 and being adapted to be engaged with and disengaged from the respective stationary contacts ,20 The said contacts 23 and 30 are in the form of metallic plates which project inward through, slots 3I` in the respective side plates 26 and 21. Each contact 29 and 30 is provided with opposite notches 23 and 3l)n and the narrower notched portion of the contact fltsther'iarrower portion of thecorresponding slot 3l. Extending transversely between the two side plates is an insulating bar 32, the ends of which project into the wider portions of the slots 3I so as to hold the contacts in place. The inner endsof the contacts engage the bar 32 at the left hand side.

. the casing I.

The two movable contacts 23 and 30 arey electrically connected with each other, this electrical connection preferably being through an electroresponsive means which is carried by and ls bodily movable withthe contact member. By preference and as shown, this electro-responsive means is a bi-metallic thrmostatic strip 34, mechanically and electrically connected directly with the two contacts. The contacts are provided with integral rearward extensions 29h, 30h which extend through corresponding apertures in the strip.` Washers 33, 35 and 36, 36 may be provided andthe rearward ends of the projections 26h, 30P may be upset or riveted over so as to hold the washers and the bi-metallic strip -in place. The bi-metallc strip 34 is adapted to serve as a latch as will be presently explained, and in order that it may more eifectively so serve it is provided with an opening at 34* and carries a wear piece 31 which is riveted in place and which is formed with two rearward extensions, one of which exy tends through the opening 34'^;

From the foregoing description it will be apparent that the contact member is movable rectilinearly as guided by the plates `I2 and 23, and that in so moving it serves to bring the movable contacts 23 and 30 into or out of engagement with the respective stationary contacts 20 and 2I to make or break the circuit. When the contact member is in the upper contact engaging position as shown in Fig. 4 electrical connection is established between the terminals I6 and I1; and when the contact member is in the lower position as shown in Fig. 8 they circuit is broken at two places, that is between the contacts 20 and 23 and between the contacts 2| and 33. f

A suitable spring means is provided for biasing the contact member inthe downward or clrcuit. opening direction. Preferably and as shown there is provided a tortional coil spring 3l positioned in a' suitable vauxiliary recess near the rear of At the ends of the spring are two integral arms 36, 33 which extend forward and bear directly against the upper ends of the plates 26 and 21. For holding the spring 33 in place in the recess there is provided a cross bar 33 which is secured in place by a screw 46. It will be observed that the main body of the spring 33 is behind the plate 26, the two arms 36, 36* projecting forward at the sides of theplate.

'For lactuating the contact member for normal Aswitching purposes, or to-eiIect closing ofthe circuit after automatic opening thereof, I provide ,a member which I shall term an actuating member or actuator. This member is normally engaged bythe thermostatic strip or latch 34, and

the actuator is so positioned and connected that a portion of the stress of actuation is transmitted directly from the actuator to the contact member independently of the thermostatic latch. The

. actuator is shown at 4I, and it is pivoted to the i contact member for movement-about a transverse 26 and 21. Spacingbushi'ngs 43, 43 hold the actuator in central position. A shoulder 4I on the actuator 4I .is adapted to engage the plate I and to thus limit relative movement of the actu.- ator inthe clock-wise direction. 'Ihe actuator tending transversely between the two side plates is provided with a tooth 4 Ib which, at normal teml neratures. is engaged by the .wear piece 31 on When the parts are in the relative positionsshown in Fig. 9 the links 44 cooperate with the handle I0 to form atoggle which locks the parts in position with the movable contacts 29 and 30' pressed into rm engagement with the stationary contacts 20 and 2|. Continued movement of the handle in the counter-clockwise direction is prevented by the engagementI of an extension 25 on the metallic piece 25 with the front guide plate I2 as shown in Fig. 9. The pivotal axis at 45 is at the left of a straight line connecting the pivotal axes at 23 and 46, and thus the handle member I0 and the links 44 serve to resist the tendency of the contact member to move downward under `the iniluencev of the spring 38 and of gravity. 'I'he spring 38 is suiilciently-I powerful to enable the said toggle action to hold the handle or operating member l0 in its lower or closedcircuit position, the toggle action resisting the tendency of the spring 24 to move the said member in the clockwise direction to its open-circuit position. f y

The above described toggle action can be released by pressing the handle upward; the parts then moving under the action of the springs 38 and'y 24 to'the open-circuit position shown in Fig. 8. 'I'he movable contacts 29 and 30 are thus disengaged from the stationary contacts 20 and 2| and the circuit is broken in two separate places. By moving the handle toward the downward position the-,several parts can be restored to their respective closed-circuit positions, as shown in' Fig. 9, andthe circuit can be thus-re-established.

-It will be evident that the force required for moving and holding the contact member is transmitted through the links 44 to the actuator. and from the actuator to the contact member. The normal. connection between the actuator and the contact member is partly through the pivot pin at 42 and partlythrough the thermostatic latch 34. By -reason of the fact that the actuator 4| engages directly with. the contact member through the pivot pin 42, the stress transmitted through the latch 34 is much less than it other-e wise would be. rlg'he tendency of the links 44 in closing the circuit is to relatively rotate the actuator in thecounter-clockwise direction, but such rotation is resisted by the'thermostatic latch 34. 'I'he said latch 34 acts at a distance from the axis 42 which is considerably greater than the distance at which the links 44 act, and the result is that the stress transmitted through the latch 34 is considerably less than that transmitted through the links 44.

As before explained, the bi-metallic strip 34 is electrically connected between the movable contacts 29 and 30. It is adapted to be deected rearward upon the passage of excessv current therethrough with the result that the wear piece 31 is disengaged from the tooth 4|b of the actuator 4|. Such disengagement permits the actuator 4| to turn slightly relatively to the contact member in the counter-clockwise direction. This yslight movement changes the relation of the toggle -links 44 and I0 and reduces the pressure which had theretofore served to hold the links 44 and the handle member I0 in their effective toggle relationship. This change in relationship and reduction in pressure permits the handle member I0 to move in the clockwise direction so as to render the toggle ineiective. Thus both the Contact member and the handle are freed and both of them move to their open-circuit positions under the'inuence of their respective springs. It will be understood that normally the contact member and the handle move substantially simultaneously with the result that the latch and the actuator may never be actually completely disengaged from each other. When the parts reach their full open-circuit position as shown in Fig. 8 the latch and the actuator are in position to fully re-engage as soon as the thermostatic strip is suiliciently cooled.

The circuit-opening movement of the contact member is not in any Way dependent on the circuit-opening movement of the handle member and will, in fact, occur even though the handle member be held in its closed-circuit position, as

shown in Fig. 10.Y The rearward deflection of the as described, be now released, it will move under the inuence of the spring 24 to its open-circuit position asV shownin Fig. 8, thus bringing the actuator 4| into its normalposition with respect to the contact member so that the tooth 4|b `is automatically engaged by the latch 34.

It will be observed that the contact member together with the actuator and the lbi-metallic thermostatic latch carried by the said contact member constitute a movable self-contained unit.

The movement of this self-contained unit is guided and controlled by the two guide plates |2 and 28, but 'inasmuch as the actuator is carried .directly by the side plates of the contact member any looseness at the guide plates will in no way atleet the accuracy or the operating characteristics of the circuit breaker. As already explained, the actuator 4| is pivoted to the contact member at 42, and the actuator and the bi-metallic latch 34 normally remain in xedrelationship with each other and with the contact member,

there being no relative movement at the bearing f 42 except upon automatic opening of the circuit breaker and even then the movement is normally very. slight. j

Preferably, as shown in Figs. 3, 9, 11 and 12, I provide in the rear wall of the casing immediately behind the engaged positions of the contacts 20, 29 and 2|, 30 two holes 41, 41. Registering holes areprovided in the plate 28. The holes 41 are useful for inspection purposes during the assembly and testing of the circuit breaker; By

looking through the holes itis possible to observe y whether the movable contacts 29 and 30 properly engage the stationary contacts 20 and 2|.v After assembly and inspection are complete the holes 41 may be closed by means of sealing wax or other suitablematerial as indicated at 48.

Preferably, though not necessarily, grooves 49,

49 are provided in the rear face of the casing I,

these grooves communicating at one end with the openings 41, 41. When the circuit breaker is intended to be used under conditions which are not 49, 49 near the ends thereof. When the holes 41, 41 are left open and when the plate 50 is provided, a tortuous passageway is provided for arcformed gases which are permitted to escape but which, on account of the length of the passage,

Y are sufficiently cooled before escaping.

What I claim is:

1. In an automatic circuit breaker, the combination of a contact member guided'for rectilinear movement and biased toward its open-circuit position, means normally serving to hold the contact member in its closed-circuit position, andI a thermostaticbi-metallic element additional to the said holding means and bodily movable in unison with the said contact member, the said element serving upon a predetermined temperature change to cause the said holding means to release the contact member and permit automatic rec- -tilinear movement thereof to its open-circuit position.

2. In an automatic circuit breaker, the combination of a contact member guided for rectilinear movement and biased toward its open-circuit position, means normally serving to hold the contact member in its closed-circuit position, and an i electro-responsive means additional to the said holding means and comprising an element inherently responsive to abnormal current conditions in the circuit, the said element being bodily movable rectilinearly in unison with the said cony tact member and serving upon the passage of excess current to cause the said holding means to release the contact member and permit automatic rectilinear movement thereof to its open-circuit position.

3. In an automatic circuit breaker, the 4combinationoi a contact member guided for rectilinear movement and biased toward its open-circuit position, a movable operating member, means controlled by the operating member for effecting movements of the contact member, the said means normally serving to hold the contact member in its closed-circuit position, and an electro- -responsive means additional to the' said movement eiecting means andA comprising an element inherently responsive to abnormal current conditions in the circuit, the said4 element being `bodily movable rectilinearly in unison with the said contact member and serving upon the passage of excess current to cause the said movement effecting means to release the contact member and permit automatic rectilinear movement thereof to its'open-circuit position.

4. In an automatic circuit breaker, the combination of a contact member guided for rectilinear movement and biased toward its vopen-circuit position, a pair of toggle links adapted when in their operativerelationship to hold the contact I member in its closed-circuit position, and anelectro-responsive means comprising an element inherently responsive to abnormal current conditions in the circuit, the said element being. bodily y movable rectilinearly in unison with the said contact member and serving lupon the passage of excess current to change the relationshipA ofthe nation of a contact member guided for rectilinearl movement and biased vtoward its open-circuit position, a pair of toggle links adapted when in their operative relationship to hold the contact memberv in its closed-circuit position, and a bimetallic element electrically connected in the circuit and bodily movable rectilinearly in unison with the said contact member, the said element serving upon the passage of excess current to change the relationship of the toggle links so as to release the contact member and permit automatic rectilinear lmovement thereof to its opencircuitposition.

6. In an automatic circuit breaker, the combination of a contact member guided for rectilinear movement and biased toward its open-circuit position, means normally serving to hold the contact member in its closed-circuit position, and a nation of a contact member guided for rectilinear movement and biased toward its open-circuit position, a pair of toggle links of which one has a pivotal connection with` the contact member, the said links when in their operative relationship serving to hold the contact member in its closed-circuit position, and a thermostatic ele- 'ment bodily movable rectilinearly in unison with the said contact member and serving upon the passage of excess current throughthe circuit to bodily move the pivotal connection between the contact member and the corresponding toggle link so as to change the relationship of the links and thereby release the contact `member and permit automatic rectilinear movement thereof to its open-circuit position.

8. In an automatic circuit breaker, the combination of a contactmember guided for rectilinear movement and biased toward its open-circuitv position, a movable'operating member, means` controlled by the operating member for effecting movements ofthe contact member, the said means being releasable independently of the operating member and normally serving `to hold the contact member in its closed-circuit position, and an electro-responsive means additional to the said movement effecting means and comprising an element inherently responsive to abnormal currentconditions in the circuit, the said element being bodily movable rectilinearly in unison with the said contact member and serving' upon the passage of excess current to cause the said movement effecting means to release the contact member independently ofl the operating member and permit automatic rectilinear movement thereof to its open-circuit position.

9. An automatic circuit'breaker comprising in combination, a pivoted operating member, a contact member guided for rectilinear movement and biased independently of the operating member toward its open-circuit position, a link pivotally connected with theoperating member and the ment of the formerl to move the latter rectilinearly for ordinary'switching purposes, the said operating member and the said link being adapted to act as toggle'links to hold the contact member in closed-circuit position, and an electro-responsive means comprising an element inherently responsive to abnormal current conditions in the circuit, the said element being bodily movable rectilinearly in unison with .the said contact member and serving upon the passage of excess current to change the position of the links with respect to the operating member so as to break the toggle said operating member when in closed-circuitv position and the said link being adapted to act` as toggle links to hold the contact member in its closed-circuit position, and an electro-responsive device connected in the circuit andbodily movable rectilinearly in unison with the' said co'ntact member, the said device serving upon the passage of excess current to change the relationship of the link with respect to the operating.

member so as to break the toggle and release.v both the operating member and the contact member and permit independent automatic movements of both of them to their respective open-circuit positions.

11. An automatic circuit breaker comprising in combination, a pivoted operating member, a contact member guided for rectilinear movement and biased independently of the operating member toward its open-circuit position, a link pivotally connected with the operating member and the contact member and serving upon pivotal movement of the former to move the latter rectilinearly for ordinaryl switching purposes, the said operating member and the said link being adapted to act as toggle links to holdthe contact member in closed-circuit position, and a curi-entcarrying bi-metallic element carried by and bodily movable with the said contact member and deflectable upon the passage of excess current to change the position of the link with respect to thev operating member so as toA break the toggle and release the contact member and permit automatic rectilinear movement thereof to its opencrcuit position independently of the operating vmember.

12. The combination in an automatic circuit breaker, of a stationary electric contact, a movable contact member guided for rectilinear movement and including an electric contact adapted toengage and disen'gage the stationary contact, the said member being biased in the contact disengaging direction, an electro-responsively controlled latch on the contact member adapted to be automatically moved from its normal relationship to the said member upon theattainment of abnormal current conditions in the circuit, a handle pivotally movable about a xed axis, and an actuating/means operatedby the lhandle and serving to move the contact member toward and hold it in its contact engaging position, the said actuating means having'an engagement with the latch adapted to be released upon automatic movement of the latter as aforesaidand the said means also having movable engagement directly with the rectilinearly movable contact member so that the force transmitted through the latch is less than the total force required for moving and holding the contact member. y

13. The combination in an automatic circuit breaker, of a stationary electric contact, a rectilinearly movable contact member including an electric contact adapted to engage and disengage the stationary contact, the said member being biased in the contact disengaging direction, an electro-responsively controlled latch carried by and bodily movable with the contact member and adapted to be automatically moved out of its normal relationship with the said member upon the attainment of abnormal current conditions in the circuit, an actuator bodily movable with the contact member and permanently connected therewith for movement relative thereto, the said actuator normally having an engagement with the latch adapted to be released upon automatic movement of the latter as aforesaid, and means for operating the said actuator to enable it to normally effect rectilinear movement of the contact member to and from its contact engaging position.

14. The combination in an automatic circuit breaker of a stationary electric contact, a rectilinearly, movable contact member including an electric contact adapted to engage and disengage the stationary contact, the said member being biased in the contact disengaging direction, an actuator bodily movable with the contact member and alsovmovable relatively thereto, an electroresponsively controlled latch attached to the contact member and projecting from the point of attachment approximately in the contact disengagi ng direction, the-said latch at its projecing end normally engaging the actuator to prevent rela.- tive movement thereof and the said latch upon theattainment of abnormal current conditions in the circuit disengaging the actuator -to Y permit relative movement thereof and to thereby permit automatic contact disengaging movement of the contact member, a handle pivotally movable about a fixed axis, and means connectingthe handle with the actuator enabling the said handle to normally movethe actuator and the contact member rectilinearly.

15. The combination in an automatic circuit breaker, of two stationary electric contacts, aV

rectilinearly movable contact member including two electric contacts adapted to engage and disengage the respective stationary contacts, the

cuit, an actuator carried by and bodily movable with the contact member and also pivotally movable relatively tothe said contact member, the

. said member being biased in the contact-djsengag-t said actuator normally having an engagement with the latch adapted to be released upon auto matic movement of the latter as aforesaid, and means for operating the said actuator to enable it to normally effect rectilinear movement of the contact member to and from its contact engaging position.

16. The combination in an automatic circuit breaker, of two opposite stationary electric contacts, a rectilinearly movable contact member including two opposite electric contacts adapted to engage and disengage the respective stationary contacts, the said member being biased in the contact disengaging direction, a U-shaped bi-metallic thermostatic current-carrying latch on the contact member and electrically connected between the two opposite movable contacts, the said latch being adapted to be automatically moved out of its normal relationship with/the said contact member upon the attainment of abnormal current conditions in the circuit, an actuator carried by and bodily movable with the contact member, and

also pivotally movable relatively to the said contact member, the sai'd actuator normally having an engagement with the latch adapted to be released upon automatic movement of the latter as aforesaid, and means for operating the said actuator to enable' it to normally effect rectilinear movement of the contact member to and froml its contact engaging position'.

17. The combination in an automatic circuit breaker, of two stationary electric contacts, a movable contact member including two transversely spaced insulating side plates and also including two separate electric contacts carried by theside plates adapted to respectively engage and disengage the stationary contacts, the said side plates having bearing surfaces whereby the contact member is guided for rectilinear movement, a bi-metallic thermostatic currentcarrying latch on the contact member and electrically connected between the two movable contacts, the said latch being adapted to be automatically moved from its normal relationship to the said contact member upon the attainment of abnormal current conditions in the circuit, an actuator positioned be'- tween the two side plates and pivotally supported thereon and normally having an engagement with the latch adapted to be released upon automatic movement of the latter as aforesaid, and means for operating the said actuator to enable it to normally eiiect rectilinear movement ofthe contactmember to and from its contact engaging position.

18. An automatic circuit breaker comprising in combination,v a rectilinearly movable contact member biased in the circuit-opening direction, an operating member pivoted for movement about a xed axis, two pivotally connected links pivoted respectively to the pivoted operating member and to the rectilinearly movable contact member and serving as an operative connection between them, an electro-responsively controlled means normally serving to :prevent pivotal movement of one of the links relatively to the contact member and serving upon the attainment of abnormal cur? rent conditions in the circuit to permit such pivotal movement, and meansA enabling the other link and the operating member to serve as a releasable toggle normally holding the contact member in closed-circuit position.

19. An automatic circuit breaker comprising in combination, a rectilinearly movable contact member biased in the circuit-opening direction, an actuator pivoted to the contact member for relative movement about a movable axis but normally held against such relative movement, op-

erating means including/toggle links connected with the actuator and when in their eective positions serving to hold the said actuator and contact 'member in their closed-circuit positions,

the said links being biased toward their inetr .effective positions as the result of pressure resulting from the said bias of the contact member, and

an electro-responsively controlled means normally serving to prevent the said pivotal movement of,.

the actuator and serving upon the attainment of abnormal current conditions in the circuit to permit such pivotal movement, the said pivotal .movement 'of theactuator serving to permit automatic rectilinear circuit-opening movement of the contact member and also serving to simultaneously release the pressure on the toggle links and thus permit them to automatically move to their opencircuit positions.

20. In an automatic circuit breaker, the combination of a casing having a recess open at the front, a plate at the front of the casi `g substantially closing the recess, a stationary contact within the casing recess, a movable Contact member within the casing recess including a contact adapted to engage and dlsengage the stationary contact, means for biasing the contact member in the contact disengaging direction, a' pivoted handle at the front of the plate, a normally operable mechanical connection between the handle and the contact member enabling the former to move the latter, and a thermostatic bi-metallic element carried by the contact member in substantially parallelism with the front plate and normally connected in the circuit, the said element being dei'lectable upon the passage of excess current therethrough to thereby render the said mechanical connection ineffective and thus permit the con- .bination of a casing having a recess open at the front, a guide plate at the front of the casing substantially closing the recess, a stationary contact within the casing recess, a rectilinearly movable contact member. within the casing recess guided at the front by the said guide plate and including a contact adapted Ato engage and disengage the stationary contact, means for biasing the contact member in the contact disengaging direction, a pivoted ha'ndle at the front of the guide plate, a normally operable mechanical .connection between the handle and the contact member enabling the former to move the latter, and an electro-responsive element .arranged to be energized upon the attainment of an abnormal currentcondition in the circuit so as to render the said mechanical connection ineffective and to thus permit the contact member to automatically move rectilinearly to its open-circuit position independently of the handle.

22. In an automatic circuit breaker, the.com bination of a `casing having a recess open at the front, a guide plate at the front o f the casing substantially closing the recess,l two stationary contacts spaced apart transversely within the casby the said guide plate and including two contacts -at the sides adapted to engage and disengage the pivoted handle lat the front of the 'guide plate, a

bodily. movable bi-metallic element electrically connected between the movable contacts and constituting at least a part of a normally operable mechanical connection between 'the/ handle and.

the contact member, the said bi-metallic element serving upon the attainment of an abnormal current condition therein to render the said mechaniing recess, a rectilinearly movable contact memi 1fber within the casing recess guided at the front es? fix/Almere c,

cal connection ineiiective and to thus permit the contact member to automatically move rectilinearly to its open-circuit position independently of the handle.

23. In an automatic circuit breaker, the combination oi a casing having a recess open at the front, an insulating guide plate at the 'front of the casing and substantially closing the recess, two conductors at the front oi the guide plate spaced apart transversely and having rearward extensions, two stationary contacts carried by the rearward extensions and positioned behind the guide plate, a rectilinearly movable contact member within the casing recess guided at the iront by the said guide plate and including two electrically connected contacts at the sides adapted to engage and disengage the stationary contacts, m'eans for biasing the said contact Amember in the contact disengaging direction, a pivoted handle at the front of the guide plate, a normally opprable mechanical connection betwecn the handle and the Contact member enabling the former to move the latter, and an electro-responsive element arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to render the said mechanical connec- .tion ineffective and to thus permit the contact member to automatically move rectilinearly to its open-circuit position independently of the handle.

24. In an automatic circuit breaker, the combination of a casing having a recess open at the front, an insulating guide plate at the front of the casing and substantially closing the recess, two conductors at the front of the guide plate spaced apart transversely and having rearward extensions, a handle at the front pivotally mounted directly on the said front conductors and having a portion extending rearward through a slot in the guide plate, two stationary contacts carried by the rearward extensions and positioned behind the guide plate, a rectilinearly movable contact member within the casing recess guided at the front by the said guide plate and including two electrically connected contacts at the sides adapted to engage and disengage the stationary contacts,'means for biasing the said 'contact member in the contact disengaging direction, a normally operable mechanical connection between the handle and the contact member, enabling the former to move the latter, and an electro-responsive element arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to render the said mechanical connection ineffective and to thus permit the contact member to automatically move rectilinearly to its open-circuit position independently of the handle.

25. In an automatic circuit breaker, the combination of a casing having a recess open at the front, an insulating guide plate at the front of the casing and substantially closing the recess, a stationary contact within the casing recess, a rectilinearly movable contact member within the casing recess guided at the front by the said guide plate and including a contact adapted to engage and disengages the stationary contact, means for biasing the contact member in the contact disengaging direction, a pivoted handle at the front of the guide plate, a stop carried by the handle and adapted to engage the inner face of the guide -plate to limit the handle movement; a normally operable mechanical connection between the handle and the contact member enabling the former to move the latter, and an electro-responsive element arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to render the said mechanical connection ineiiective and to thus permit the contact member to automatically move rectilinearly to its open-,circuit position independently of the handle.

26. In an automatic circuit breaker, the combination of a casing having a recess open at the front, an insulating guide plate at the front of the casing and substantially closing the recess, a stationary contact within the casing recess, a rectilinearly movable contact member within the casing recess guided at the front by the said guide plate and including a Contact adapted to engage and disengage the stationary contact, means for biasing the contact member in the contact disengaging direction, an actuator pivoted to the contact member and bodily movable therewith, a bi-rnetallic current-carrying releasable latch normally holding the actuator against pivotal movement in one direction relatively to the contact member and serving upon the attainment of abnormal current conditions in the circuit to release the actuator and permit it to move in the last said direction, a stop on the actuator directly engaging the front guide plate to limit pivotal movement in the opposite direction, and means engaging the actuator to normally move the contact member to open or close the circuit.

27. An automatic circuit breaker comprising in combination, a casing having a recess open at the iront, a stationary contact within the casing recess, a rectilinearly movable contact member within the casing recess including a contact adapted to engage and disengage the said stationary'contact, a movable handle, a normally'operable mechanical connection between the handle and the contact member enabling the former to move the latter, an electro-responsive element arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to render the said mechanical connection ineiiective and to thus permit the contact member to move rectilinearly to its open-circuit position independently of the handle, and a coil torsional spring carried by the casing and having an integral arm in contact with the contact member, the said spring serving to bias the contact member for movement in the circuit-opening direction.

28. An automatic circuit breaker comprising in combination, a casing .having a main recess open at the front and an auxiliary recess at the rear of the main recess, a stationary contact within the main casing recess, a. rectilinearly movable contact member within the main casing recess including a contact adapted to engage and disengage the said stationary contact, a movable handle, a normally operable mechanical connection between the handle and the contact member enabling the former to-move thelatter, an electro-responsive element arranged to be energized upon the attainment ofl an abnormal current condition in the circuit so as to render the said mechanical connection ineiective and to thus permit the contact member to move rectilinearly to its open-circuit position independently of the handle, a coil torsional `spring in the auxiliary recess in the casing and having an integral arm in contact with the contact member, the said spring serving to bias the contact member for movement in the circuit-opening direction, and a cross bar in the auxiliary recess within the coil of the spring for holding the spring in place.

29. An automatic circuit breaker comprising in combination, a casing having a recess open at the rEST AVAILABLE COt front, two stationary contacts spaced apart transversely within the casing recess, a contact member within the casing recess rectilinearly movable between the stationary contacts and including two insulating side plates spaced apart transversely and electrically connected contacts carried by the side plates and adapted to engage and disengage the said stationary contacts, a movable handle, a normally operable mechanical connection between the handle and the contact member enabling the former to move the latter, an electro-responsive element arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to render the said mechanical connection ineffective and to thus permit the contact member to move rectilinearly to its open-circuit position independently of the handle. and a coil torsional spring carried by the casing near the rear thereof and having at its ends two integral arms in contact with the respective side plates of the contact member, the said spring serving to bias the contact member for movement in the circuit opening direction.

30. An automatic circuit breaker comprising in combination, a casing having a main recess open at the front and an auxiliary recess at the rear of the main recess, two stationary contacts spaced apart transversely within the main casing recess,

contacts and including two electrically connectedcontacts at the sides adapted to engage and disengage the said stationary contacts, a movable handle, a normally operable mechanical connection between the handle and the contact member enabling the former to move the latter, an electro-responsive element arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to render the said mechanical connection ineffective andto thus permit the contact member to move rectillnearly to its open-circuit position independently of the handle, a coil torsional spring in the auxiliary recess in the casing and having an integral arm in contact with the contact member, the said spring serving to bias the Contact member for movement in the circuit-opening direction, and a plate at the rear of the main recess covering the auxiliary recess and serving as a 'guide for the movable contact member.

DISCLAIMER- 2,09,963.-Josept Sachs, West Hartford, Conn. AUTOMATIC CIRCUIT BREAKER.

Patent dated October 5, 1937.

Disclaimer led April 12, 1943, by the assignee, Colts Patent Fire Arms Manufacturing Company. Hereby enters this disclaimer of claim '14 in said patent.

[Olict'al Gazette ay 4,1943] JOSEPH SACHS. v 

